The correct answer is C. reverse osmosis.
Reverse osmosis is a process that uses pressure to force water molecules through a semipermeable membrane, which allows water molecules to pass through but not other molecules, such as salt. This process can be used to remove salt and other impurities from water, making it safe to drink.
Centrifugation is a process that uses centrifugal force to separate substances of different densities. This process can be used to separate salt from water, but it does not remove other impurities.
Plasmolysis is a process that occurs when a cell is placed in a solution with a higher concentration of solutes than the cell’s cytoplasm. This causes the cell’s cytoplasm to shrink, and the cell membrane to pull away from the cell wall. This process does not remove salt from water.
Sedimentation is a process that separates substances based on their density. This process can be used to separate salt from water, but it does not remove other impurities.
In conclusion, the correct answer is C. reverse osmosis.